Avidity Biosciences (RNA) 10-Q 8 Nov 23 2023 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2023	Oct. 23, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-39321
Entity Registrant Name	Avidity Biosciences, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1336960
Entity Address, Address Line One	10578 Science Center Drive
Entity Address, Address Line Two	Suite 125
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	401-7900
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	RNA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		74,101,254
Entity Central Index Key	0001599901
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 85,650	$ 340,396
Marketable securities	456,933	270,331
Prepaid and other assets	12,904	12,215
Total current assets	555,487	622,942
Property and equipment, net	8,130	6,254
Restricted cash	295	251
Right-of-use assets	8,907	8,755
Other assets	344	598
Total assets	573,163	638,800
Current liabilities:
Accounts payable and accrued liabilities	31,981	32,572
Accrued compensation	11,165	11,190
Lease liabilities, current portion	3,602	3,105
Deferred revenue, current portion	1,968	5,041
Total current liabilities	48,716	51,908
Lease liabilities, net of current portion	6,979	7,582
Deferred revenue, net of current portion	0	1,235
Total liabilities	55,695	60,725
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock, $0.0001 par value; authorized shares – 400,000; issued and outstanding shares – 74,101 and 69,768 at September 30, 2023 and December 31, 2022, respectively	7	7
Additional paid-in capital	1,029,660	939,310
Accumulated other comprehensive loss	(1,878)	(2,698)
Accumulated deficit	(510,321)	(358,544)
Total stockholders’ equity	517,468	578,075
Total liabilities and stockholders’ equity	$ 573,163	$ 638,800

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	74,101,000	69,768,000
Common stock, shares outstanding (in shares)	74,101,000	69,768,000

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Collaboration revenue	$ 2,818	$ 2,482	$ 7,367	$ 6,455
Operating expenses:
Research and development	47,714	37,317	138,151	104,794
General and administrative	13,729	10,094	38,071	27,349
Total operating expenses	61,443	47,411	176,222	132,143
Loss from operations	(58,625)	(44,929)	(168,855)	(125,688)
Other income (expense):
Interest income	6,280	1,342	17,567	2,203
Other expense	(13)	(12)	(489)	(39)
Total other income	6,267	1,330	17,078	2,164
Net loss	(52,358)	(43,599)	(151,777)	(123,524)
Other comprehensive income (loss):
Net unrealized gains (losses) on marketable securities	788	(477)	820	(3,276)
Comprehensive loss	$ (51,570)	$ (44,076)	$ (150,957)	$ (126,800)
Net loss per share, basic (in dollars per share)	$ (0.71)	$ (0.82)	$ (2.11)	$ (2.45)
Net loss per share, diluted (in dollars per share)	$ (0.71)	$ (0.82)	$ (2.11)	$ (2.45)
Weighted-average shares outstanding, basic (in shares)	74,097	53,069	71,987	50,432
Weighted-average shares outstanding, diluted (in shares)	74,097	53,069	71,987	50,432

Condensed Statements of Stockho

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2021		47,754,000
Beginning balance at Dec. 31, 2021	$ 381,430	$ 5	$ 566,161	$ (187)	$ (184,549)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		7,000
Issuance of common stock upon exercise of stock options	10		10
Issuance of common stock in public offerings, net of issuance costs (in shares)		1,520,000
Issuance of common stock in public offerings, net of issuance costs	24,103		24,103
Vesting of early exercise options	1		1
Stock-based compensation	6,238		6,238
Net loss	(34,235)				(34,235)
Other comprehensive income (loss)	(1,839)			(1,839)
Ending balance (in shares) at Mar. 31, 2022		49,281,000
Ending balance at Mar. 31, 2022	375,708	$ 5	596,513	(2,026)	(218,784)
Beginning balance (in shares) at Dec. 31, 2021		47,754,000
Beginning balance at Dec. 31, 2021	381,430	$ 5	566,161	(187)	(184,549)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(123,524)
Ending balance (in shares) at Sep. 30, 2022		54,446,000
Ending balance at Sep. 30, 2022	376,982	$ 5	688,513	(3,463)	(308,073)
Beginning balance (in shares) at Mar. 31, 2022		49,281,000
Beginning balance at Mar. 31, 2022	375,708	$ 5	596,513	(2,026)	(218,784)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		5,000
Issuance of common stock upon exercise of stock options	4		4
Issuance of common stock in public offerings, net of issuance costs (in shares)		2,746,000
Issuance of common stock in public offerings, net of issuance costs	38,281		38,281
Vesting of early exercise options	1		1
Issuance of common stock under Employee Stock Purchase Plan (in shares)		49,000
Issuance of common stock under Employee Stock Purchase Plan	499		499
Stock-based compensation	6,508		6,508
Net loss	(45,690)				(45,690)
Other comprehensive income (loss)	(960)			(960)
Ending balance (in shares) at Jun. 30, 2022		52,081,000
Ending balance at Jun. 30, 2022	374,351	$ 5	641,806	(2,986)	(264,474)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		270,000
Issuance of common stock upon exercise of stock options	303		303
Issuance of common stock in public offerings, net of issuance costs (in shares)		2,095,000
Issuance of common stock in public offerings, net of issuance costs	39,317		39,317
Vesting of early exercise options	1		1
Stock-based compensation	7,086		7,086
Net loss	(43,599)				(43,599)
Other comprehensive income (loss)	(477)			(477)
Ending balance (in shares) at Sep. 30, 2022		54,446,000
Ending balance at Sep. 30, 2022	$ 376,982	$ 5	688,513	(3,463)	(308,073)
Beginning balance (in shares) at Dec. 31, 2022	69,768,000	69,768,000
Beginning balance at Dec. 31, 2022	$ 578,075	$ 7	939,310	(2,698)	(358,544)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		102,000
Issuance of common stock upon exercise of stock options	520		520
Issuance of common stock in public offerings, net of issuance costs (in shares)		943,000
Issuance of common stock in public offerings, net of issuance costs	22,441		22,441
Stock-based compensation	9,104		9,104
Net loss	(52,394)				(52,394)
Other comprehensive income (loss)	1,169			1,169
Ending balance (in shares) at Mar. 31, 2023		70,813,000
Ending balance at Mar. 31, 2023	$ 558,915	$ 7	971,375	(1,529)	(410,938)
Beginning balance (in shares) at Dec. 31, 2022	69,768,000	69,768,000
Beginning balance at Dec. 31, 2022	$ 578,075	$ 7	939,310	(2,698)	(358,544)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	145,000
Net loss	$ (151,777)
Ending balance (in shares) at Sep. 30, 2023	74,101,000	74,101,000
Ending balance at Sep. 30, 2023	$ 517,468	$ 7	1,029,660	(1,878)	(510,321)
Beginning balance (in shares) at Mar. 31, 2023		70,813,000
Beginning balance at Mar. 31, 2023	558,915	$ 7	971,375	(1,529)	(410,938)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		12,000
Issuance of common stock upon exercise of stock options	7		7
Issuance of common stock in public offerings, net of issuance costs (in shares)		3,164,000
Issuance of common stock in public offerings, net of issuance costs	38,106		38,106
Issuance of common stock under Employee Stock Purchase Plan (in shares)		81,000
Issuance of common stock under Employee Stock Purchase Plan	859		859
Stock-based compensation	9,453		9,453
Net loss	(47,025)				(47,025)
Other comprehensive income (loss)	(1,137)			(1,137)
Ending balance (in shares) at Jun. 30, 2023		74,070,000
Ending balance at Jun. 30, 2023	559,178	$ 7	1,019,800	(2,666)	(457,963)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		31,000
Issuance of common stock upon exercise of stock options	40		40
Stock-based compensation	9,820		9,820
Net loss	(52,358)				(52,358)
Other comprehensive income (loss)	$ 788			788
Ending balance (in shares) at Sep. 30, 2023	74,101,000	74,101,000
Ending balance at Sep. 30, 2023	$ 517,468	$ 7	$ 1,029,660	$ (1,878)	$ (510,321)

Condensed Statements of Stock_2

Condensed Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Public offering issuance costs	$ 977	$ 408	$ 1,216	$ 1,184	$ 745

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (151,777)	$ (123,524)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,486	1,006
Stock-based compensation expense	28,377	19,832
Amortization of premiums and discounts on marketable securities, net	(8,037)	184
Non-cash operating lease costs	2,154	2,068
Changes in operating assets and liabilities:
Prepaid and other assets	(435)	(3,242)
Accounts payable and accrued liabilities	(588)	12,028
Accrued compensation	(25)	(1,193)
Operating lease liabilities	(2,412)	(1,002)
Deferred revenue	(4,308)	(3,236)
Net cash used in operating activities	(135,565)	(97,079)
Cash flows from investing activities
Maturities of marketable securities	229,450	85,975
Purchases of marketable securities	(407,195)	(266,189)
Purchases of property and equipment	(3,365)	(1,973)
Net cash used in investing activities	(181,110)	(182,187)
Cash flows from financing activities
Proceeds from issuance of common stock in public offerings, net of issuance costs	60,547	101,701
Proceeds from issuance of common stock under employee incentive equity plans	1,426	816
Net cash provided by financing activities	61,973	102,517
Net decrease in cash, cash equivalents and restricted cash	(254,702)	(176,749)
Cash, cash equivalents and restricted cash at beginning of period	340,647	320,699
Cash, cash equivalents and restricted cash at end of period	85,945	143,950
Supplemental schedule of noncash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	$ 1,741	$ 0

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Description of Business Avidity Biosciences, Inc. (the Company or Avidity) is a biopharmaceutical company committed to delivering a new class of RNA therapeutics called Antibody Oligonucleotide Conjugates (AOCs). The Company’s proprietary AOC platform is designed to combine the specificity of monoclonal antibodies with the precision of RNA therapeutics to target the root cause of diseases previously untreatable with such therapeutics. Liquidity On June 16, 2020, the Company completed its initial public offering (IPO), and it has since raised additional capital in the public markets as described further in Note 8 (Stockholders’ Equity). To date, the Company has devoted substantially all of its resources to organizing and staffing the Company, business planning, raising capital, developing its proprietary AOC platform, identifying potential product candidates, establishing its intellectual property portfolio, conducting research, preclinical and clinical studies, and providing other general and administrative support for these operations. In addition, the Company has a limited operating history, has incurred operating losses since inception and expects that it will continue to incur net losses into the foreseeable future as it continues the development of its product candidates and development programs. As of September 30, 2023, the Company had an accumulated deficit of $510.3 million and cash, cash equivalents and marketable securities of $542.6 million. The Company believes that existing cash, cash equivalents and marketable securities will be sufficient to fund the Company’s operations for at least 12 months from the date of the filing of this Form 10-Q. The Company plans to finance its future cash needs through equity offerings, debt financings or other capital sources, including potential collaborations, licenses and other arrangements. If the Company is not able to secure adequate additional funding, it may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible, and/or delay or reduce the scope of its planned development programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the Securities and Exchange Commission (SEC) related to a quarterly report on Form 10-Q. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The unaudited interim condensed financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these unaudited interim condensed financial statements are not necessarily indicative of the results that may be expected for any future periods. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2022 included in the Company’s annual report on Form 10-K filed with the SEC on February 28, 2023. Immaterial Out of Period Adjustment During the nine months ended September 30, 2023, the Company identified an immaterial adjustment to research and development expenses that impacted the Company’s previously issued quarterly and annual financial statements. Therefore, the Company recorded an out of period adjustment that decreased research and development expenses for the nine months ended September 30, 2023 by $3.6 million, which related to periods prior to 2023.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The Company’s condensed financial statements are prepared in accordance with GAAP, which requires the Company to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the condensed financial statements and accompanying notes. The most significant estimates in the Company’s condensed financial statements relate to revenue recognition, stock-based compensation, and accrued research and development costs. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Summary of Significant Accounting Policies The Company’s significant accounting policies are discussed in “Note 2 – Summary of Significant Accounting Policies” of the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022 filed with the SEC on February 28, 2023. There have been no significant changes to these policies during the nine months ended September 30, 2023. Marketable Securities The Company’s marketable securities primarily consist of U.S. Government and corporate debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets on the balance sheets. The Company made an accounting policy election to (1) not measure an allowance for credit loss for accrued interest receivable, and (2) to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which it determines the accrued interest will not be collected. See Note 4 (Marketable Securities) for further information. Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has established guidelines regarding approved investments, credit quality, diversification, liquidity and maturities of investments, which are designed to maintain safety and liquidity. The Company has not experienced any losses in its accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institutions in which those deposits are held. Accounts Payable and Accrued Liabilities (in thousands) September 30, December 31, Accounts payable $ 5,550 $ 4,637 Accrued non-clinical liabilities 21,006 22,535 Accrued clinical liabilities 5,425 5,400 Total accounts payable and accrued liabilities $ 31,981 $ 32,572 Research and Development Costs and Accruals Research and development costs are expensed as incurred and include salaries, benefits and stock-based compensation associated with research and development personnel, third-party research and development expenses, license fees, laboratory supplies, facilities, overhead costs, and consultants. Nonrefundable advance payments for goods and services that will be used in future research and development activities are capitalized and recorded as expense in the period that the Company receives the goods or when services are performed. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying condensed balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the services, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Upfront and milestone payments to acquire contractual rights to licensed technology are expensed when incurred if there is uncertainty in the Company receiving future economic benefit from the acquired contractual rights. Certain of these contractual rights may require the Company to make additional milestone payments upon initiation of a pivotal trial and the U.S. Food and Drug Administration approval, which are not expected to exceed $10.9 million. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, adjusted for the weighted-average number of common shares outstanding that are subject to repurchase or forfeiture. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the common stock equivalent securities would be anti-dilutive. Common stock equivalent securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares; in thousands): September 30, 2023 2022 Common stock options 12,526 9,093 Restricted stock units 701 — Performance stock units 750 — Employee Stock Purchase Plan shares pending issuance 109 27 Total 14,086 9,120 Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued Accounting Standards Update (ASU 2016-13), Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires that an entity measure and recognize expected credit losses for financial assets held at amortized cost and replaces the incurred loss impairment methodology, and establishes additional disclosures related to credit risks. ASU 2016-13 also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. The Company adopted ASU 2016-13 on January 1, 2023. The adoption of the new standard did not have a material impact on the Company’s condensed financial statements.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company determines the fair value of its marketable securities based on one or more valuations from its investment and reporting service provider. The investment service provider values the securities using a hierarchical security pricing model that relies primarily on valuations provided by an industry-recognized valuation service. Such valuations may be based on the following: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs, such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The following tables summarize the Company’s cash equivalents and marketable securities measured at fair value (in thousands): Fair Value Measurements Using As of September 30, 2023 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 4,982 $ 4,982 $ — $ — Marketable securities: U.S. Treasury securities 443,385 443,385 — — U.S. Government agency securities 4,990 — 4,990 — Negotiable certificates of deposit 7,313 — 7,313 — Corporate debt securities 1,245 — 1,245 — Total $ 461,915 $ 448,367 $ 13,548 $ — Fair Value Measurements Using As of December 31, 2022 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 2,498 $ 2,498 $ — $ — Marketable securities: U.S. Treasury securities 244,945 244,945 — — U.S. Government agency securities 4,966 — 4,966 — Negotiable certificates of deposit 4,346 — 4,346 — Corporate debt securities 16,074 — 16,074 — Total $ 272,829 $ 247,443 $ 25,386 $ —

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	Marketable Securities The Company’s marketable securities, which consist of highly liquid marketable debt securities, are classified as available-for-sale and are stated at fair value. The following tables summarize the Company’s marketable securities (in thousands): As of September 30, 2023 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 318,419 $ 1 $ (1,142) $ 317,278 U.S. Government agency securities 1 or less 5,000 — (10) 4,990 Negotiable certificates of deposit 1 or less 5,880 — (21) 5,859 Corporate debt securities 1 or less 1,256 — (11) 1,245 U.S. Treasury securities 1 - 2 126,786 — (679) 126,107 Negotiable certificates of deposit 1 - 2 1,470 — (16) 1,454 Total $ 458,811 $ 1 $ (1,879) $ 456,933 As of December 31, 2022 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 230,349 $ 1 $ (2,283) $ 228,067 U.S. Government agency securities 1 or less 5,000 — (34) 4,966 Negotiable certificates of deposit 1 or less 3,911 1 (57) 3,855 Corporate debt securities 1 or less 16,360 — (286) 16,074 U.S. Treasury securities 1 - 2 16,919 — (41) 16,878 Negotiable certificates of deposit 1 - 2 490 1 — 491 Total $ 273,029 $ 3 $ (2,701) $ 270,331 The unrealized losses on the Company’s marketable securities of $1.9 million as of September 30, 2023, $0.2 million of which were in a continuous unrealized loss position of greater than 12 months, were caused by interest rate increases which resulted in the decrease in market value of these securities. Because the decline in fair value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity, there were no allowances for credit losses at September 30, 2023 and December 31, 2022. Accrued interest receivable on available-for-sale securities was $2.3 million and $1.3 million at September 30, 2023 and December 31, 2022, respectively. We have not written off any accrued interest receivable for the three or nine months ended September 30, 2023 and 2022.

Collaboration, License and Rese

Collaboration, License and Research Agreements	9 Months Ended
	Sep. 30, 2023
Collaboration License And Research Agreements [Abstract]
Collaboration, License and Research Agreements	Collaboration, License and Research Agreements Research Collaboration and License Agreement with Eli Lilly and Company In April 2019, the Company entered into a Research Collaboration and License Agreement (the Lilly Agreement) with Eli Lilly and Company (Lilly) for the discovery, development and commercialization of AOC products directed against certain targets in immunology and other select indications on a worldwide basis. In connection with the Lilly Agreement, the Company recognized revenue of $2.8 million and $2.4 million for the three months ended September 30, 2023 and 2022, respectively, and $7.3 million and $6.3 million for the nine months ended September 30, 2023 and 2022, respectively. Collaboration receivables related to the Lilly Agreement were $1.0 million and $2.1 million as of September 30, 2023 and December 31, 2022, respectively, which are included in prepaid and other assets on the condensed balance sheets. Research Agreement with MyoKardia, Inc. In December 2020, the Company entered into a research collaboration (the MyoKardia Agreement) with MyoKardia, Inc. (MyoKardia), a wholly-owned subsidiary of Bristol Myers Squibb, to demonstrate the potential utility of AOCs in cardiac tissue by leveraging MyoKardia’s genetic cardiomyopathy platform including, among other aspects, its novel target discovery engine and proprietary cardiac disease models. In connection with the MyoKardia Agreement, the Company recognized an immaterial amount of revenue in each of the periods presented. Through September 30, 2023, the aggregate funding received from collaboration and research service agreements was $42.3 million. A reconciliation of the closing balance of deferred revenue related to the Company's research collaboration and license agreements is as follows (in thousands): Balance at December 31, 2022 $ 6,276 Revenue recognized that was included in the balance at the beginning of the period (4,308) Balance at September 30, 2023 $ 1,968

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment consist of the following (in thousands): September 30, December 31, Laboratory equipment $ 10,350 $ 7,217 Computers and software 127 116 Office furniture and equipment 1,979 1,792 Leasehold improvements 280 249 Property and equipment, gross 12,736 9,374 Less accumulated depreciation (4,606) (3,120) Total property and equipment, net $ 8,130 $ 6,254 Depreciation expense related to property and equipment was $0.6 million and $0.4 million for the three months ended September 30, 2023 and 2022, respectively, and $1.5 million and $1.0 million for the nine months ended September 30, 2023 and 2022, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Litigation Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. There are no claims or actions pending or threatened against the Company that, if adversely determined, would in management’s judgment have a material adverse effect on the Company. Contractual Obligations The Company enters into contracts in the normal course of business for contract research services, contract manufacturing services, professional services, and other services and products for operating purposes. These contracts may include certain provisions that could require payments for early termination. The amount of any such termination payments will vary depending on the timing of the termination and the specific terms of the contract.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Amended and Restated Certificate of Incorporation On June 16, 2020, the Company’s certificate of incorporation was amended and restated to authorize 400,000,000 shares of common stock and 40,000,000 shares of undesignated preferred stock, each with a par value of $0.0001 per share. There was no preferred stock outstanding during the periods presented in the condensed financial statements. Common Stock On July 2, 2021, the Company entered into a sales agreement (the 2021 Sales Agreement) with Cowen and Company, LLC (the Sales Agent), under which the Company may, from time to time, sell shares of its common stock having an aggregate offering price of up to $150.0 million through the Sales Agent. Sales of the Company’s common stock made pursuant to the 2021 Sales Agreement are made under the Company’s shelf registration statement on Form S-3, which became automatically effective upon filing on July 2, 2021 (the Shelf Registration Statement). During the nine months ended September 30, 2022, the Company sold 7,141,761 shares of its common stock pursuant to the 2021 Sales Agreement and received net proceeds of $121.3 million, after deducting offering-related transaction costs and commissions. On November 8, 2022, the Company entered into a sales agreement (the 2022 Sales Agreement) with the Sales Agent, with substantially similar terms as the 2021 Sales Agreement. Under the 2022 Sales Agreement, the Company may, from time to time, sell shares of its common stock having an aggregate offering price of up to $200.0 million through the Sales Agent. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Sales Agent. The Company is not obligated to sell, and the Sales Agent is not obligated to buy or sell, any shares of common stock under the 2022 Sales Agreement. Upon entry into the 2022 Sales Agreement, the 2021 Sales Agreement was terminated. During the nine months ended September 30, 2023, the Company sold 4,107,810 shares of its common stock pursuant to the 2022 Sales Agreement and received net proceeds of $60.5 million, after deducting offering-related transaction costs and commissions. On December 15, 2022, the Company completed a public offering of 13,800,000 shares of its common stock at a public offering price of $17.25 per share. The net proceeds from the offering were $223.8 million, after deducting underwriting discounts, commissions and offering costs of $14.3 million. The shares sold in the offering were registered pursuant to the Company’s Shelf Registration Statement. Stock Options Stock option activity for employee and non-employee awards and related information is as follows (in thousands, except per share data): Number of Weighted- Outstanding at December 31, 2022 9,352 $ 15.28 Granted 3,885 14.77 Exercised (145) 3.88 Forfeited/expired (566) 19.19 Outstanding at September 30, 2023 12,526 $ 15.08 Restricted Stock Units and Performance Stock Units During the nine months ended September 30, 2023, under the 2020 Incentive Award Plan and the 2022 Employment Inducement Incentive Award Plan, the Company granted restricted stock units (RSUs) and performance stock units (PSUs) to employees of the Company. RSUs are valued at the market price of a share of the Company’s stock on the date of grant. RSUs vest ratably on an annual basis over a four-year service period and are payable in shares of common stock on the vesting date. Compensation expense for RSUs is recognized on a straight-line basis over the four-year service period. Forfeitures are recorded in the period in which they occur. The following table summarizes the RSU activity for the nine months ended September 30, 2023 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2022 — $ — Granted 757 20.03 Vested — — Forfeited (56) 20.70 Unvested at September 30, 2023 701 $ 19.98 During the nine months ended September 30, 2023, the Company granted 750,000 PSUs at a weighted-average grant date fair value of $6.57 per share. The PSUs vest upon achievement of certain clinical milestones and continued employment thereafter. The PSUs have a two-year term and any unvested awards at the end of the term will be forfeited. Compensation expense for PSUs is recognized on a straight-line basis over the requisite service periods when the achievement of the performance condition is determined to be probable. If a performance condition is not determined to be probable or is not met, no stock-based compensation expense is recognized, and any previously recognized expense is reversed. Forfeitures are recognized as a reduction of stock-based compensation expense in the period they occur. There were no PSUs outstanding as of December 31, 2022. As of September 30, 2023, no PSUs were vested and no stock-based compensation expense was recognized as the performance conditions were not deemed probable. Employee Stock Purchase Plan The Company issued 81,005 and 48,760 shares of common stock under the Employee Stock Purchase Plan (ESPP) during the nine months ended September 30, 2023 and 2022, respectively. The Company had an outstanding liability of $0.6 million at September 30, 2023, which is included in accounts payable and accrued liabilities on the condensed balance sheet, for employee contributions to the ESPP for shares pending issuance at the end of the current offering period. As of September 30, 2023, 467,023 shares of common stock were available for issuance under the ESPP. Stock-Based Compensation Expense The assumptions used in the Black-Scholes model to determine the fair value of stock option grants were as follows: Options ESPP Nine Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Risk-free interest rate 3.5% - 4.5% 1.5% - 3.4% 5.4% 2.2% Expected volatility 80% - 82% 85% 76% 79% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 0.5 0.5 Expected dividend yield —% —% —% —% Risk-Free Interest Rate. The Company bases the risk-free interest rate assumption for equity awards on the rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the award being valued. Expected Volatility. The expected volatility of stock options is estimated based on the average historical volatilities of common stock of comparable publicly traded companies and the Company's own volatility. The comparable companies are chosen based on their size and stage in the life cycle. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available. Prior to 2023, the Company exclusively used peer group companies to determine expected volatility. Expected Term. The Company's limited option exercise history does not provide a reasonable basis for estimating expected term, therefore the Company has estimated the expected life of its stock options using the simplified method, whereby the expected life equals the average of the vesting term and the original contractual term of the option. The expected life assumption for employee stock purchases under the ESPP is six months to conform with the six-month ESPP offering period. Expected Dividend Yield. The Company’s expected dividend yield assumption is zero as it has never paid dividends and has no present intention to do so in the future. The allocation of stock-based compensation expense for stock option, RSU awards, PSU awards, and shares purchasable under the ESPP was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development expense $ 5,611 $ 4,151 $ 16,325 $ 10,948 General and administrative expense 4,209 2,935 12,052 8,884 Total stock-based compensation expense $ 9,820 $ 7,086 $ 28,377 $ 19,832 As of September 30, 2023, the unrecognized compensation cost related to outstanding time-based options and RSUs was $75.1 million and $11.8 million, respectively, which is expected to be recognized over a weighted-average period of 2.7 years and 3.4 years, respectively. Unrecognized compensation cost related to PSUs was $4.9 million. As of September 30, 2023, the unrecognized compensation cost related to stock purchase rights under the ESPP was $0.2 million, which is expected to be recognized over a weighted-average period of 0.2 years.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net loss	$ (52,358)	$ (47,025)	$ (52,394)	$ (43,599)	$ (45,690)	$ (34,235)	$ (151,777)	$ (123,524)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		From time to time, our officers (as defined in Rule 16a–1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K). During the three months ended September 30, 2023, our officers and directors took the following actions with respect to 10b5-1 trading arrangements: Action Date Trading Arrangement Total Shares to be Sold Expiration Date Rule 10b5-1 Non-Rule 10b5-1 Sarah Boyce (President, Chief Executive Officer and Director) Adopt 9/26/2023 X (1) (2) Michael MacLean (Chief Financial and Chief Business Officer) Adopt 9/27/2023 X (1) (2) Michael Flanagan (Chief Scientific and Technical Officer) Adopt 9/26/2023 X (1) (2) Teresa McCarthy (Chief Human Resources Officer) Adopt 9/26/2023 X (1) (2) Arthur Levin, Ph.D.(Distinguished Scientist and Strategic Leader; Director) Adopt 9/27/2023 X (1) (2) ____________________ (1) Under our 2020 Incentive Award Plan, recipients of RSUs and PSUs are required to sell a number of shares that satisfies applicable tax withholding obligations upon a taxable event such as a vesting date. Each participant listed in this table has executed an instruction letter to our broker for the sale of such minimum number of shares, at the then-applicable market price, sufficient to cover applicable tax withholding obligations, at the statutory minimum applicable statutory rate, for each such person. These instruction letters qualify as Rule 10b5-1 trading arrangements but may exist concurrent with another 10b5-1 trading arrangement for the same individual, as permitted by Rule 10b5-1(c)(1)(ii)(D)(3) under the Exchange Act. (2) These instruction letters shall remain in effect for so long as the individual owns RSUs or PSUs.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Sarah Boyce [Member]
Trading Arrangements, by Individual
Name	Sarah Boyce
Title	(President, Chief Executive Officer and Director)
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	9/26/2023
Michael MacLean [Member]
Trading Arrangements, by Individual
Name	Michael MacLean
Title	(Chief Financial and Chief Business Officer)
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	9/27/2023
Michael Flanagan [Member]
Trading Arrangements, by Individual
Name	Michael Flanagan
Title	(Chief Scientific and Technical Officer)
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	9/26/2023
Teresa McCarthy [Member]
Trading Arrangements, by Individual
Name	Teresa McCarthy
Title	(Chief Human Resources Officer)
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	9/26/2023
Arthur Levin, Ph.D. [Member]
Trading Arrangements, by Individual
Name	Arthur Levin, Ph.D.
Title	(Distinguished Scientist and Strategic Leader; Director)
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	9/27/2023

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and the rules and regulations of the Securities and Exchange Commission (SEC) related to a quarterly report on Form 10-Q. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The unaudited interim condensed financial statements reflect all adjustments which, in the opinion of management, are necessary for a fair statement of the results for the periods presented. All such adjustments are of a normal and recurring nature. The operating results presented in these unaudited interim condensed financial statements are not necessarily indicative of the results that may be expected for any future periods. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2022 included in the Company’s annual report on Form 10-K filed with the SEC on February 28, 2023.
Use of Estimates	Use of Estimates The Company’s condensed financial statements are prepared in accordance with GAAP, which requires the Company to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the condensed financial statements and accompanying notes. The most significant estimates in the Company’s condensed financial statements relate to revenue recognition, stock-based compensation, and accrued research and development costs. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Marketable Securities	Marketable Securities The Company’s marketable securities primarily consist of U.S. Government and corporate debt securities. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income. There were no realized gains and losses during the periods presented. At each balance sheet date, the Company assesses available-for-sale debt securities in an unrealized loss position to determine whether the unrealized loss or any potential credit losses should be recognized in net income (loss). For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through net income (loss). For available-for-sale securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers the severity of the impairment, any changes in interest rates, underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded as an allowance in interest income. There have been no impairment or credit losses recognized during the periods presented. The Company excludes the applicable accrued interest from both the fair value and amortized costs basis of the Company’s available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded within prepaid and other assets on the balance sheets. The Company made an accounting policy election to (1) not measure an allowance for credit loss for accrued interest receivable, and (2) to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which the Company considers to be in the period in which it determines the accrued interest will not be collected.
Concentration of Credit Risk	Concentration of Credit RiskFinancial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has established guidelines regarding approved investments, credit quality, diversification, liquidity and maturities of investments, which are designed to maintain safety and liquidity. The Company has not experienced any losses in its accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institutions in which those deposits are held.
Research and Development Costs and Accruals	Research and Development Costs and Accruals Research and development costs are expensed as incurred and include salaries, benefits and stock-based compensation associated with research and development personnel, third-party research and development expenses, license fees, laboratory supplies, facilities, overhead costs, and consultants. Nonrefundable advance payments for goods and services that will be used in future research and development activities are capitalized and recorded as expense in the period that the Company receives the goods or when services are performed. The Company has entered into various research and development contracts with research institutions, clinical research organizations, clinical manufacturing organizations and other companies. Payments for these activities are based on the terms of the individual agreements, which may differ from the pattern of costs incurred, and payments made in advance of performance are reflected in the accompanying condensed balance sheets as prepaid and other assets or accrued liabilities. The Company records accruals for estimated costs incurred for ongoing research and development activities. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the services, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Upfront and milestone payments to acquire contractual rights to licensed technology are expensed when incurred if there is uncertainty in the Company receiving future economic benefit from the acquired contractual rights. Certain of these contractual rights may require the Company to make additional milestone payments upon initiation of a pivotal trial and the U.S. Food and Drug Administration approval, which are not expected to exceed $10.9 million.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, adjusted for the weighted-average number of common shares outstanding that are subject to repurchase or forfeiture. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the common stock equivalent securities would be anti-dilutive.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. Recently Adopted Accounting Pronouncements In June 2016, the FASB issued Accounting Standards Update (ASU 2016-13), Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments. ASU 2016-13 requires that an entity measure and recognize expected credit losses for financial assets held at amortized cost and replaces the incurred loss impairment methodology, and establishes additional disclosures related to credit risks. ASU 2016-13 also eliminates the concept of “other-than-temporary” impairment when evaluating available-for-sale debt securities and instead focuses on determining whether any impairment is a result of a credit loss or other factors. An entity will recognize an allowance for credit losses on available-for-sale debt securities rather than an other-than-temporary impairment that reduces the cost basis of the investment. The Company adopted ASU 2016-13 on January 1, 2023. The adoption of the new standard did not have a material impact on the Company’s condensed financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities (in thousands) September 30, December 31, Accounts payable $ 5,550 $ 4,637 Accrued non-clinical liabilities 21,006 22,535 Accrued clinical liabilities 5,425 5,400 Total accounts payable and accrued liabilities $ 31,981 $ 32,572
Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share	Common stock equivalent securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares; in thousands): September 30, 2023 2022 Common stock options 12,526 9,093 Restricted stock units 701 — Performance stock units 750 — Employee Stock Purchase Plan shares pending issuance 109 27 Total 14,086 9,120

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Cash Equivalents and Marketable Securities Measured at Fair Value	The following tables summarize the Company’s cash equivalents and marketable securities measured at fair value (in thousands): Fair Value Measurements Using As of September 30, 2023 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 4,982 $ 4,982 $ — $ — Marketable securities: U.S. Treasury securities 443,385 443,385 — — U.S. Government agency securities 4,990 — 4,990 — Negotiable certificates of deposit 7,313 — 7,313 — Corporate debt securities 1,245 — 1,245 — Total $ 461,915 $ 448,367 $ 13,548 $ — Fair Value Measurements Using As of December 31, 2022 Total Quoted Prices in Significant Significant Cash equivalents: U.S. Treasury securities $ 2,498 $ 2,498 $ — $ — Marketable securities: U.S. Treasury securities 244,945 244,945 — — U.S. Government agency securities 4,966 — 4,966 — Negotiable certificates of deposit 4,346 — 4,346 — Corporate debt securities 16,074 — 16,074 — Total $ 272,829 $ 247,443 $ 25,386 $ —

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities	The Company’s marketable securities, which consist of highly liquid marketable debt securities, are classified as available-for-sale and are stated at fair value. The following tables summarize the Company’s marketable securities (in thousands): As of September 30, 2023 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 318,419 $ 1 $ (1,142) $ 317,278 U.S. Government agency securities 1 or less 5,000 — (10) 4,990 Negotiable certificates of deposit 1 or less 5,880 — (21) 5,859 Corporate debt securities 1 or less 1,256 — (11) 1,245 U.S. Treasury securities 1 - 2 126,786 — (679) 126,107 Negotiable certificates of deposit 1 - 2 1,470 — (16) 1,454 Total $ 458,811 $ 1 $ (1,879) $ 456,933 As of December 31, 2022 Maturity Amortized Unrealized Unrealized Estimated U.S. Treasury securities 1 or less $ 230,349 $ 1 $ (2,283) $ 228,067 U.S. Government agency securities 1 or less 5,000 — (34) 4,966 Negotiable certificates of deposit 1 or less 3,911 1 (57) 3,855 Corporate debt securities 1 or less 16,360 — (286) 16,074 U.S. Treasury securities 1 - 2 16,919 — (41) 16,878 Negotiable certificates of deposit 1 - 2 490 1 — 491 Total $ 273,029 $ 3 $ (2,701) $ 270,331

Collaboration, License and Re_2

Collaboration, License and Research Agreements (Tables)	9 Months Ended
	Sep. 30, 2023
Collaboration License And Research Agreements [Abstract]
Summary of Reconciliation of Deferred	A reconciliation of the closing balance of deferred revenue related to the Company's research collaboration and license agreements is as follows (in thousands): Balance at December 31, 2022 $ 6,276 Revenue recognized that was included in the balance at the beginning of the period (4,308) Balance at September 30, 2023 $ 1,968

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following (in thousands): September 30, December 31, Laboratory equipment $ 10,350 $ 7,217 Computers and software 127 116 Office furniture and equipment 1,979 1,792 Leasehold improvements 280 249 Property and equipment, gross 12,736 9,374 Less accumulated depreciation (4,606) (3,120) Total property and equipment, net $ 8,130 $ 6,254

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Summary of Stock Option Activity	Stock option activity for employee and non-employee awards and related information is as follows (in thousands, except per share data): Number of Weighted- Outstanding at December 31, 2022 9,352 $ 15.28 Granted 3,885 14.77 Exercised (145) 3.88 Forfeited/expired (566) 19.19 Outstanding at September 30, 2023 12,526 $ 15.08
Schedule of Unvested Restricted Stock Units Roll Forward	The following table summarizes the RSU activity for the nine months ended September 30, 2023 (in thousands, except per share data): Number of Shares Weighted-Average Grant Date Fair Value Unvested at December 31, 2022 — $ — Granted 757 20.03 Vested — — Forfeited (56) 20.70 Unvested at September 30, 2023 701 $ 19.98
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions	The assumptions used in the Black-Scholes model to determine the fair value of stock option grants were as follows: Options ESPP Nine Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Risk-free interest rate 3.5% - 4.5% 1.5% - 3.4% 5.4% 2.2% Expected volatility 80% - 82% 85% 76% 79% Expected term (in years) 5.5 - 6.1 5.5 - 6.1 0.5 0.5 Expected dividend yield —% —% —% —%
Schedule of Allocated Stock-based Compensation Expense	The allocation of stock-based compensation expense for stock option, RSU awards, PSU awards, and shares purchasable under the ESPP was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Research and development expense $ 5,611 $ 4,151 $ 16,325 $ 10,948 General and administrative expense 4,209 2,935 12,052 8,884 Total stock-based compensation expense $ 9,820 $ 7,086 $ 28,377 $ 19,832

Description of Business and B_2

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated deficit	$ (510,321)		$ (510,321)		$ (358,544)
Cash, cash equivalents and marketable securities	542,600		542,600
Research and development	$ (47,714)	$ (37,317)	(138,151)	$ (104,794)
Revision of Prior Period, Adjustment | Related to Periods Prior to 2023
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Research and development			$ 3,600

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Realized gains and losses on marketable securities	$ 0	$ 0	$ 0	$ 0
Other-than-temporary impairments on marketable securities	0	0	0	0
Credit loss expense	0	$ 0	0	$ 0
License
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum milestone payments to acquire contractual rights to licensed technology	$ 10,900,000		$ 10,900,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounting Policies [Abstract]
Accounts payable	$ 5,550	$ 4,637
Accrued non-clinical liabilities	21,006	22,535
Accrued clinical liabilities	5,425	5,400
Total accounts payable and accrued liabilities	$ 31,981	$ 32,572

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	14,086	9,120
Common stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	12,526	9,093
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	701	0
Performance stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	750	0
Employee Stock Purchase Plan shares pending issuance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	109	27

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	$ 456,933	$ 270,331
Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	461,915	272,829
Recurring | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	4,982	2,498
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	448,367	247,443
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	4,982	2,498
Recurring | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	13,548	25,386
Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Recurring | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total	0	0
Recurring | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents:	0	0
Recurring | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	443,385	244,945
Recurring | U.S. Treasury securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	443,385	244,945
Recurring | U.S. Treasury securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | U.S. Treasury securities | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	4,990	4,966
Recurring | U.S. Government agency securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | U.S. Government agency securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	4,990	4,966
Recurring | U.S. Government agency securities | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Negotiable certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	7,313	4,346
Recurring | Negotiable certificates of deposit | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Negotiable certificates of deposit | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	7,313	4,346
Recurring | Negotiable certificates of deposit | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Corporate debt securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	1,245	16,074
Recurring | Corporate debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	0	0
Recurring | Corporate debt securities | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	1,245	16,074
Recurring | Corporate debt securities | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities:	$ 0	$ 0

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 458,811	$ 273,029
Unrealized Gains	1	3
Unrealized Losses	(1,879)	(2,701)
Estimated Fair Value, current	456,933	270,331
Estimated Fair Value	456,933	270,331
U.S. Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	318,419	230,349
Amortized Cost, noncurrent	126,786	16,919
Estimated Fair Value, current	317,278	228,067
Estimated Fair Value, noncurrent	126,107	16,878
U.S. Treasury securities | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	1	1
Unrealized Losses	(1,142)	(2,283)
U.S. Treasury securities | 1 - 2
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	0
Unrealized Losses	(679)	(41)
U.S. Government agency securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	5,000	5,000
Estimated Fair Value, current	4,990	4,966
U.S. Government agency securities | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	0
Unrealized Losses	(10)	(34)
Negotiable certificates of deposit
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	5,880	3,911
Amortized Cost, noncurrent	1,470	490
Estimated Fair Value, current	5,859	3,855
Estimated Fair Value, noncurrent	1,454	491
Negotiable certificates of deposit | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	1
Unrealized Losses	(21)	(57)
Negotiable certificates of deposit | 1 - 2
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	1
Unrealized Losses	(16)	0
Corporate debt securities
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost, current	1,256	16,360
Estimated Fair Value, current	1,245	16,074
Corporate debt securities | 1 or less
Schedule Of Available For Sale Securities [Line Items]
Unrealized Gains	0	0
Unrealized Losses	$ (11)	$ (286)

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Debt Securities, available-for-sale, unrealized loss	$ (1,879,000)		$ (1,879,000)		$ (2,701,000)
Unrealized losses position for 12 month or greater	200,000		200,000
Allowance for credit loss	0		0		0
Accrued interest receivable on available-for-sale securities	2,300,000		2,300,000		$ 1,300,000
Debt securities, available-for-sale, accrued interest writeoff	$ 0	$ 0	$ 0	$ 0

Collaboration, License and Re_3

Collaboration, License and Research Agreements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		33 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Dec. 31, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized	$ 2,818	$ 2,482	$ 7,367	$ 6,455
Aggregate funding received from collaboration and research service agreements					$ 42,300
Research Collaboration and License Agreement with Eli Lilly
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized	2,800	$ 2,400	7,300	$ 6,300
Collaboration receivables	$ 1,000		$ 1,000		$ 1,000	$ 2,100

Collaboration, License and Re_4

Collaboration, License and Research Agreements - Reconciliation of Deferred Revenue (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Contract With Customer, Liability [Roll Forward]
Balance	$ 6,276
Revenue recognized	(4,308)
Balance	$ 1,968

Property and Equipment, net - S

Property and Equipment, net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 12,736	$ 9,374
Less accumulated depreciation	(4,606)	(3,120)
Total property and equipment, net	8,130	6,254
Laboratory equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	10,350	7,217
Computers and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	127	116
Office furniture and equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,979	1,792
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 280	$ 249

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation expenses related to property and equipment	$ 600	$ 400	$ 1,486	$ 1,006

Commitments and Contingencies (

Commitments and Contingencies (Details)	Sep. 30, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Loss contingencies accrued	$ 0

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)				3 Months Ended						9 Months Ended
	Dec. 15, 2022	Nov. 08, 2022	Jul. 02, 2021	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Jun. 16, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares authorized (in shares)				400,000,000						400,000,000		400,000,000	400,000,000
Preferred stock, shares authorized (in shares)													40,000,000
Common stock, par value (in dollars per share)				$ 0.0001						$ 0.0001		$ 0.0001	$ 0.0001
Preferred stock, par value (in dollars per share)													$ 0.0001
Preferred stock, shares outstanding (in shares)				0						0		0
Proceeds from issuance of common stock in public offerings, net of issuance costs										$ 60,547,000	$ 101,701,000
Public offering issuance costs					$ 977,000	$ 408,000	$ 1,216,000	$ 1,184,000	$ 745,000
Stock-based compensation expense				$ 9,820,000			$ 7,086,000			$ 28,377,000	$ 19,832,000
Expected dividend yield										0%
Unrecognized compensation cost, options				$ 75,100,000						$ 75,100,000
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period										4 years
Granted (in shares)										757,000
Granted (in dollars per share)										$ 20.03
PSUs outstanding (in shares)				701,000						701,000		0
PSUs vested (in shares)										0
Unrecognized compensation cost, excluding options				$ 11,800,000						$ 11,800,000
Compensation cost, period for recognition										4 years
Restricted Stock Units (RSUs) | Weighted Average
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation cost, period for recognition										3 years 4 months 24 days
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield										0%	0%
Compensation cost, period for recognition										2 years 8 months 12 days
Performance stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)										750,000
Granted (in dollars per share)										$ 6.57
Expiration period										2 years
PSUs outstanding (in shares)												0
PSUs vested (in shares)										0
Stock-based compensation expense										$ 0
Unrecognized compensation cost, excluding options				4,900,000						$ 4,900,000
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued under ESPP (in shares)										81,005	48,760
Outstanding liability				$ 600,000						$ 600,000
Shares reserved for future issuance (in shares)				467,023						467,023
Expected term (in years)										6 months	6 months
Award offering period										6 months
Expected dividend yield										0%	0%
Unrecognized compensation cost, excluding options				$ 200,000						$ 200,000
Compensation cost, period for recognition										2 months 12 days
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued under ESPP (in shares)					81,000			49,000
Follow-on Public Offering | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of stock number of shares issued in transaction (in shares)	13,800,000
Sale of stock, price per share (in dollars per share)	$ 17.25
Proceeds from the follow-on public offering, net of underwriting discounts, commissions and offering costs	$ 223,800,000
Public offering issuance costs	$ 14,300,000
Cowen And Company, LLC | Private Placement, 2021 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of common stock maximum aggregate offering price			$ 150,000,000
Sale of stock number of shares issued in transaction (in shares)											7,141,761
Proceeds from issuance of common stock in public offerings, net of issuance costs											$ 121,300,000
Cowen And Company, LLC | Private Placement, 2022 Sales Agreement
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale of common stock maximum aggregate offering price		$ 200,000,000
Sale of stock number of shares issued in transaction (in shares)										4,107,810
Proceeds from issuance of common stock in public offerings, net of issuance costs										$ 60,500,000

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2023 $ / shares shares	Dec. 31, 2022 $ / shares
Number of Options
Beginning balance (in shares)	9,352
Granted (in shares)	3,885
Exercised (in shares)	(145)
Forfeited/expired (in shares)	(566)
Ending balance (in shares)	12,526
Weighted- Average Exercise Price Per Share
Outstanding (in dollars per share) | $ / shares	$ 15.08	$ 15.28
Granted (in dollars per share) | $ / shares	14.77
Exercised (in dollars per share) | $ / shares	3.88
Forfeited/expired (in dollars per share) | $ / shares	$ 19.19

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Unvested Restricted Stock Units Roll Forward (Details) - Restricted Stock Units (RSUs) shares in Thousands	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Number of Shares
Beginning balance (in shares) | shares	0
Granted (in shares) | shares	757
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(56)
Ending balance (in shares) | shares	701
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	20.03
Vested (in dollars per share) | $ / shares	0
Forfeited (in dollars per share) | $ / shares	20.70
Ending balance (in dollars per share) | $ / shares	$ 19.98

Stockholders' Equity - Schedu_2

Stockholders' Equity - Schedule of Assumptions to Determine Fair Value (Details)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0%
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	3.50%	1.50%
Risk-free interest rate, Maximum	4.50%	3.40%
Expected volatility, Minimum	80%
Expected volatility, Maximum	82%
Expected volatility		85%
Expected dividend yield	0%	0%
Stock Options | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 6 months
Stock Options | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	5.40%	2.20%
Expected volatility	76%	79%
Expected term (in years)	6 months	6 months
Expected dividend yield	0%	0%

Stockholders' Equity - Schedu_3

Stockholders' Equity - Schedule of Allocated Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 9,820	$ 7,086	$ 28,377	$ 19,832
Research and development expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	5,611	4,151	16,325	10,948
General and administrative expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,209	$ 2,935	$ 12,052	$ 8,884